Home values fell 3% in the first quarter from the previous quarter and 1.1% in March from the previous month, pushed down by an abundance of foreclosed homes on the market, according to data to be released Monday by real-estate website Zillow.com. Prices have now fallen for 57 consecutive months, according to Zillow.

Stan Humphries, Zillow's chief economist, now believes prices won't hit bottom before next year and expects they will fall by another 7% to 9%.

While some analysts have argued that home prices need to fall to "clearing prices" that will attract more buyers, price declines could also complicate any recovery by pushing more borrowers under water. Zillow estimates that more than 28% of borrowers owe more than their homes are worth nationally. Those numbers are much higher in hard-hit markets such as Phoenix, where more than two-thirds of borrowers owe more than their homes are worth.